Maybe something like this?
CREATE PROCEDURE spDoSearch
@FirstName varchar(25) = null,
@LastName varchar(25) = null,
@Title varchar(25) = null
AS BEGIN
SELECT ID, FirstName, LastName, Title FROM tblUsers
WHERE (@FirstName IS NULL OR FirstName = @FirstName)
AND (@LastNameName IS NULL OR LastName = @LastName)
AND (@Title IS NULL OR Title = @Title)END
Best Wishes,
thank you in advanve for help and support,
Jacek